During the coming year our investigations will center around three areas. The first involves studies of the color coding properties of area 17 cells. We will continue to examine the receptive field organization of both X and Y cells for pure color stimuli. The second area of research will involve extending our studies of complex, two-dimensional patterns into the color domain. We will examine the responses of area 17 cells to pure-color checkerboards of various length/width ratios. We will compare these responses to those elicited by gratings and plaids. The third area of research will involve human psychophysical studies of the interaction between patterns based on luminance differences and patterns based on pure color differences. We shall also examine the detectability of various pseudo-random dot patterns with known frequency spectra.